Apparatus for optical inspection of wafers during polishing

• US 20070123151A1
• Filed: 01/29/2007
• Published: 05/31/2007
• Est. Priority Date: 05/23/1995
• Status: Abandoned Application

• Current Assignee: Nova Measuring Instruments Limited (Honeywell International Inc.)
• Original Assignee: Nova Measuring Instruments Limited (Honeywell International Inc.)
• Inventors: Finarov, Moshe
• Application Number:
  US11/698,878
• Publication Number:
  US 20070123151A1
• Time in Patent Office: Days
• US Class Current: 451/6
• CPC Class Codes: B24B 37/04 designed for working plane surfaces
• CPC Class Codes: B24B 49/12 involving optical means

Abstract

The present invention is aimed to provide a measurement system installable within a processing equipment and more specifically within the exit station of a polishing machine. The optical scheme of this system includes a spectrophotometric channel, an imaging channel and also means for holding the wafer under measurement.

Claims

1. A measurement station for use with a processing machine, which includes a processing station for processing an article and an exit station including an article transfer means and at least one articles'"'"' cassette, the measurement station being so dimensioned as to be installable in association with the exit station of the processing machine and comprising a spectrophotometric measuring unit and a holding unit for receiving and holding the article in a measuring position during measurements, said measuring unit comprising an optical system including an imaging system operable to locate measurements;

a beam directing assembly for directing illuminating light towards the article and directing collected light from the article towards a beam splitting assembly for separating a first portion of the collected light to propagate towards the spectrophotometric measuring unit and a second portion to propagate to said imaging system.

2. The measurement station according to claim 1, wherein said beam splitting assembly comprising an inclined mirror surface.

3. The measurement station according to claim 1, wherein said beam splitting assembly comprising a pin hole mirror.

4. The processing machine according to claim 1, wherein said imaging system comprises a charge coupled device (CCD).

5. The measurement station according to claim 1, wherein said measuring unit is operable to measure a thickness of at least a top layer of the article.

6. The measurement station according to claim 1, wherein said measuring unit is operable to carry out optical inspection of the processed article.

7. The measurement station according to claim 1, comprising a support assembly for supporting the article.

8. The measurement station according to claim 7, wherein said support assembly is configured for supporting the article that is to be received from the holding unit.

9. The measurement station according to claim 7, wherein said support assembly is configured for supporting the article that is to be received by the holding unit.

10. The measurement station according to claim 8, wherein said support assembly is configured for supporting the article that is to be received by the holding unit.

11. The measurement station according to claim 1, wherein the measuring and holding units are separated by a window through which at least a part of the article being held is viewable to enable optical measurements.

12. The measurement station according to claim 1, wherein said holding unit comprises an assembly movable along an axis perpendicular to the article'"'"'s surface, thereby enabling said holding of the article in the measuring position.

13. The measurement station according to claim 1, having a footprint in at least one dimension of about a size of the article'"'"'s diameter.

14. The measurement station according to claim 1, wherein said processing station is a polisher.

15. The measurement station according to claim 1, and also comprising a robot in said article transfer means for supplying the processed article to the measurement station.

16. The measurement station according to claim 1, wherein said optical system includes a focusing optics for focusing the illuminated light onto the article and collecting the light from the illuminated article.

17. The measurement station according to claim 7, wherein the support assembly is configured to receive the article from the article transfer means of the exit station and to enable the article transfer into the measuring position.

18. The measurement station according to claim 7, wherein the support assembly includes two support elements displaceable with respect to each other.

19. The measurement station according to claim 7, wherein the support assembly is configured for supporting the article at its periphery region.

20. The measurement station according to claim 1, wherein the optical imaging system is operable to perform pattern recognition.

21. The measurement station according to claim 16, wherein the measuring unit comprises a fiber optics for directing light from a light source towards the focusing optics.

22. The measurement station according to claim 16, wherein the focusing optics comprises an objective lens arrangement.

23. The measurement station according to claim 1, wherein the imaging system includes a lens arrangement accommodated between an imaging detector and the beam splitting assembly.

24. The measurement station according to claim 1, wherein the spectrophotometric measuring unit comprises a lens arrangement accommodated between the beam splitting assembly and the spectrophotometer.

25. The measurement station according to claim 1, wherein the optical system is configured for providing substantially normal incidence of the illuminating light.

26. The measurement station according to claim 3, wherein the pin hole mirror is accommodated so as to be an aperture stop in an optical path of the collected light, the pin hole mirror thereby appearing as a dark area in an image of a measurement spot on the article and allowing for locating the measurement spot.

27. The measurement station according to claim 1, wherein the holding unit comprises a vacuum assembly for holding the article by vacuum.

28. The measurement station according to claim 7, wherein the support assembly includes two support elements displaceable with respect to each other.

29. The measurement station according to claim 1, wherein said measurement station is installable within the exit station of the processing machine.

30. The measurement station according to claim 1, wherein said measuring unit is configured and operable to measure in the patterned article.

31. The measurement station according to claim 2, wherein said inclined mirror surface is a surface of a pin hole mirror.

32. The processing machine according to claim 2, wherein said imaging system comprises a charge coupled device (CCD).

33. The measurement station according to claim 2, wherein said measuring unit is operable to measure a thickness of at least a top layer of the article.

34. The measurement station according to claim 2, wherein said measuring unit is operable to carry out optical inspection of the processed article.

35. The measurement station according to claim 2, comprising a support assembly for supporting the article.

36. The measurement station according to claim 35, wherein said support assembly is configured for supporting the article that is to be received from the holding unit.

37. The measurement station according to claim 35, wherein said support assembly is configured for supporting the article that is to be received by the holding unit.

38. The measurement station according to claim 36, wherein said support assembly is configured for supporting the article that is to be received by the holding unit.

39. The measurement station according to claim 2, wherein the measuring and holding units are separated by a window through which at least a part of the article being held is viewable to enable optical measurements.

40. The measurement station according to claim 2, wherein said holding unit comprises an assembly movable along an axis perpendicular to the article'"'"'s surface, thereby enabling said holding of the article in the measuring position.

41. The measurement station according to claim 2, having a footprint in at least one dimension of about a size of the article'"'"'s diameter.

42. The measurement station according to claim 2, wherein said processing station is a polisher.

43. The measurement station according to claim 2, and also comprising a robot in said article transfer means for supplying the processed article to the measurement station.

44. The measurement station according to claim 2, wherein said optical system includes a focusing optics for focusing the illuminated light onto the article and collecting the light from the illuminated article.

45. The measurement station according to claim 35, wherein the support assembly is configured to receive the article from the article transfer means of the exit station and to enable the article transfer into the measuring position.

46. The measurement station according to claim 35, wherein the support assembly includes two support elements displaceable with respect to each other.

47. The measurement station according to claim 35, wherein the support assembly is configured for supporting the article at its periphery region.

48. The measurement station according to claim 2, wherein the optical imaging system is operable to perform pattern recognition.

49. The measurement station according to claim 44, wherein the measuring unit comprises a fiber optics for directing light from a light source towards the focusing optics.

50. The measurement station according to claim 44, wherein the focusing optics comprises an objective lens arrangement.

51. The measurement station according to claim 2, wherein the imaging system includes a lens arrangement accommodated between an imaging detector and the beam splitting assembly.

52. The measurement station according to claim 2, wherein the spectrophotometric measuring unit comprises a lens arrangement accommodated between the beam splitting assembly and the spectrophotometer.

53. The measurement station according to claim 2, wherein the optical system is configured for providing substantially normal incidence of the illuminating light.

54. The measurement station according to claim 31, wherein the pin hole mirror is accommodated so as to be an aperture stop in an optical path of the collected light, the pin hole mirror thereby appearing as a dark area in an image of a measurement spot on the article and allowing for locating the measurement spot.

55. The measurement station according to claim 2, wherein the holding unit comprises a vacuum assembly for holding the article by vacuum.

56. The measurement station according to claim 35, wherein the support assembly includes two support elements displaceable with respect to each other.

57. The measurement station according to claim 2, wherein said measurement station is installable within the exit station of the processing machine.

58. The measurement station according to claim 2, wherein said measuring unit is configured and operable to measure in the patterned article.

59. The measurement station according to claim 5, comprising a support assembly for supporting the article.

60. The measurement station according to claim 59, wherein said support assembly is configured for supporting the article that is to be received from the holding unit.

61. The measurement station according to claim 59, wherein said support assembly is configured for supporting the article that is to be received by the holding unit.

62. The measurement station according to claim 60, wherein said support assembly is configured for supporting the article that is to be received by the holding unit.

63. The measurement station according to claim 5, wherein the measuring and holding units are separated by a window through which at least a part of the article being held is viewable to enable optical measurements.

64. The measurement station according to claim 5, wherein said holding unit comprises an assembly movable along an axis perpendicular to the article'"'"'s surface, thereby enabling said holding of the article in the measuring position.

65. The measurement station according to claim 5, having a footprint in at least one dimension of about a size of the article'"'"'s diameter.

66. The measurement station according to claim 5, wherein said processing station is a polisher.

67. The measurement station according to claim 5, and also comprising a robot in said article transfer means for supplying the processed article to the measurement station.

68. The measurement station according to claim 5, wherein said optical system includes a focusing optics for focusing the illuminated light onto the article and collecting the light from the illuminated article.

69. The measurement station according to claim 59, wherein the support assembly is configured to receive the article from the article transfer means of the exit station and to enable the article transfer into the measuring position.

70. The measurement station according to claim 59, wherein the support assembly includes two support elements displaceable with respect to each other.

71. The measurement station according to claim 59, wherein the support assembly is configured for supporting the article at its periphery region.

72. The measurement station according to claim 5, wherein the optical imaging system is operable to perform pattern recognition.

73. The measurement station according to claim 68, wherein the measuring unit comprises a fiber optics for directing light from a light source towards the focusing optics.

74. The measurement station according to claim 68, wherein the focusing optics comprises an objective lens arrangement.

75. The measurement station according to claim 5, wherein the imaging system includes a lens arrangement accommodated between an imaging detector and the beam splitting assembly.

76. The measurement station according to claim 5, wherein the spectrophotometric measuring unit comprises a lens arrangement accommodated between the beam splitting assembly and the spectrophotometer.

77. The measurement station according to claim 5, wherein the optical system is configured for providing substantially normal incidence of the illuminating light.

78. The measurement station according to claim 5, wherein the beam splitting means comprises a pin hole mirror that is accommodated so as to be an aperture stop in an optical path of the collected light, the pin hole mirror thereby appearing as a dark area in an image of a measurement spot on the article and allowing for locating the measurement spot.

79. The measurement station according to claim 5, wherein the holding unit comprises a vacuum assembly for holding the article by vacuum.

80. The measurement station according to claim 59, wherein the support assembly includes two support elements displaceable with respect to each other.

81. The measurement station according to claim 5, wherein said measurement station is installable within the exit station of the processing machine.

82. The measurement station according to claim 5, wherein said measuring unit is configured and operable to measure in the patterned article.

83. The measurement station according to claim 7, wherein the measuring and holding units are separated by a window through which at least a part of the article being held is viewable to enable optical measurements.

84. The measurement station according to claim 7, wherein said holding unit comprises an assembly movable along an axis perpendicular to the article'"'"'s surface, thereby enabling said holding of the article in the measuring position.

85. The measurement station according to claim 7, having a footprint in at least one dimension of about a size of the article'"'"'s diameter.

86. The measurement station according to claim 7, wherein said processing station is a polisher.

87. The measurement station according to claim 7, and also comprising a robot in said article transfer means for supplying the processed article to the measurement station.

88. The measurement station according to claim 7, wherein said optical system includes a focusing optics for focusing the illuminated light onto the article and collecting the light from the illuminated article.

89. The measurement station according to claim 7, wherein the optical imaging system is operable to perform pattern recognition.

90. The measurement station according to claim 88, wherein the measuring unit comprises a fiber optics for directing light from a light source towards the focusing optics.

91. The measurement station according to claim 88, wherein the focusing optics comprises an objective lens arrangement.

92. The measurement station according to claim 7, wherein the imaging system includes a lens arrangement accommodated between an imaging detector and the beam splitting assembly.

93. The measurement station according to claim 7, wherein the spectrophotometric measuring unit comprises a lens arrangement accommodated between the beam splitting assembly and the spectrophotometer.

94. The measurement station according to claim 7, wherein the optical system is configured for providing substantially normal incidence of the illuminating light.

95. The measurement station according to claim 7, wherein the beam splitting means comprises a pin hole mirror that is accommodated so as to be an aperture stop in an optical path of the collected light, the pin hole mirror thereby appearing as a dark area in an image of a measurement spot on the article and allowing for locating the measurement spot.

96. The measurement station according to claim 7, wherein the holding unit comprises a vacuum assembly for holding the article by vacuum.

97. The measurement station according to claim 7, wherein said measurement station is installable within the exit station of the processing machine.

98. The measurement station according to claim 7, wherein said measuring unit is configured and operable to measure in the patterned article.

99. The measurement station according to claim 13, wherein said processing station is a polisher.

100. The measurement station according to claim 13, and also comprising a robot in said article transfer means for supplying the processed article to the measurement station.

101. The measurement station according to claim 13, wherein said optical system includes a focusing optics for focusing the illuminated light onto the article and collecting the light from the illuminated article.

102. The measurement station according to claim 13, wherein the optical imaging system is operable to perform pattern recognition.

103. The measurement station according to claim 101, wherein the measuring unit comprises a fiber optics for directing light from a light source towards the focusing optics.

104. The measurement station according to claim 101, wherein the focusing optics comprises an objective lens arrangement.

105. The measurement station according to claim 13, wherein the imaging system includes a lens arrangement accommodated between an imaging detector and the beam splitting assembly.

106. The measurement station according to claim 13, wherein the spectrophotometric measuring unit comprises a lens arrangement accommodated between the beam splitting assembly and the spectrophotometer.

107. The measurement station according to claim 13, wherein the optical system is configured for providing substantially normal incidence of the illuminating light.

108. The measurement station according to claim 13, wherein the beam splitting means comprises a pin hole mirror that is accommodated so as to be an aperture stop in an optical path of the collected light, the pin hole mirror thereby appearing as a dark area in an image of a measurement spot on the article and allowing for locating the measurement spot.

109. The measurement station according to claim 13, wherein the holding unit comprises a vacuum assembly for holding the article by vacuum.

110. The measurement station according to claim 13, wherein said measurement station is installable within the exit station of the processing machine.

111. The measurement station according to claim 13, wherein said measuring unit is configured and operable to measure in the patterned article.

112. A measurement station for use with a processing machine, which includes a polisher for polishing an article and an exit station including an article transfer means and at least one articles'"'"' cassette, the measurement station being so dimensioned as to be installable in association with the exit station of the processing machine and comprising a spectrophotometric measuring unit and a holding unit for receiving and holding the article in a measuring position during measurements, said measuring unit comprising an optical system including an imaging system operable to locate measurements;

a beam directing assembly for directing illuminating light towards the article and directing collected light from the article towards a beam splitting assembly including a pin hole mirror for separating a first portion of the collected light to propagate towards the spectrophotometric measuring unit and a second portion to propagate to said imaging system.

113. A measurement station for use with a processing machine, which includes a processing station for processing an article and an exit station including an article transfer means and at least one articles'"'"' cassette, the measurement station being so dimensioned as to be installable in association with the exit station of the processing machine and comprising a spectrophotometric measuring unit, a holding unit for receiving and holding the article in a measuring position during measurements, and a support assembly for supporting the article while transporting it in between said transfer means and said holding unit, said measuring unit being configured and operable to measure a thickness of at least a top layer of the article, said measuring unit comprising an optical system including an imaging system operable to locate measurements;

a beam directing assembly for directing illuminating light towards the article and directing collected light from the article towards a beam splitting assembly for separating a first portion of the collected light to propagate towards the spectrophotometric measuring unit and a second portion to propagate to said imaging system.

114. A measurement station for use with a processing machine, which includes a processing station for processing an article and an exit station including an article transfer means and at least one articles'"'"' cassette, the measurement station being so dimensioned as to be installable in association with the exit station of the processing machine and comprising a spectrophotometric measuring unit and a holding unit for receiving and holding the article in a measuring position during measurements, said measuring unit being configured and operable to measure a thickness of at least a top layer of the article, said measuring unit comprising an optical system including an imaging system operable to locate measurements;

a beam directing assembly for directing illuminating light towards the article and directing collected light from the article towards a beam splitting assembly including a pin hole mirror for separating a first portion of the collected light to propagate towards the spectrophotometric measuring unit and a second portion to propagate to said imaging system.